* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    text-decoration: none;
    list-style: none;
    font-family: 微软雅黑;
}

.container::after {
    content: "";
    display: table;
    clear: both;
}

header {
    background: #6BC2EF;
}

nav {
    padding-top: 11px;
    padding-bottom: 11px;
}

.container {
    width: 870px;
    margin: auto;
}

.nav-left, .nav-center, .nav-right {
    width: 33.333333%;
    float: left;
}

.nav-left {
    height: 56px;
}

.nav-center {
    text-align: center;
}

.nav-right {
    text-align: right;
}

.nav-right a {
    color: #ffffff;
    font-size: 12px;
    font-weight: bold;
    text-align: right;
}

.nav-right a img {
    display: none;
}

 .banner .col {
    width: 50%;
    float: left;
}

.banner{
    color: #ffffff;
    overflow: hidden;
}

.banner p {
    font-weight: bold;
    margin-bottom: 5px;
    margin-top: 15px;
}

.banner h1{
    font-weight: 100;
    margin-bottom: 25px;
    font-size: 36px;
}
.banner a{
    background-color: #2996cc;
    padding: 15px 53px;
    font-weight: bold;
    color: #fff;
    font-size: 12px;
    display: inline-block;
    border-radius: 2px;
    transition: .5s;

}
.banner a:hover{
    background-color:#1882b7;
}
.banner img{
    width: 100%;
    display: block;
}
main{
    margin-bottom: 60px;
    margin-top: 60px;
}
main .col{
    width: 25%;
    float: left;
    text-align: center;
    padding-left: 10px;
    padding-right:10px;
}
main img{
    margin-bottom: 10px;
}
main h3{
    font-size: 14px;
    margin-bottom: 10px;
}
main p{
    font-size: 14px;
    color: #657082;
}
.download{
    border-top: 1px solid #e0e0e0;
    text-align: center;
    margin-top: 60px;
    padding-top: 60px;
}
.download h2{
    margin-bottom: 15px;
}
.download p{
    margin-bottom: 25px;
}
.download a{
    display: inline-block;
}
.download img{
    margin-bottom: 0;
    margin-left: 8px;
    margin-right: 8px;
}
footer{
    width: 100%;
    background-color: #1b2126;
    color: #6a777b;
    padding-top: 60px;
    padding-bottom: 60px;
}

@media (max-width:550px){
        .container{
            width: 80%;
        }
    .nav-right span{
        display: none;
    }
     nav .nav-right a img{
        display: inline-block;
        margin-right: 15px;
         margin-top: 8px;
    }
    .banner .col{
        width: 100%;
        text-align: center;
    }
    .banner a{
        margin-bottom: 25px;
    }
    .banner img{
        width: 80%
    }
    main .col{
        width: 100%;
    }
}